V8: Let peek-gn use mb to reuse v8-side configs.

scripts/slave/recipe_modules/v8/api.py

 # Copyright 2013 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 import argparse
 import datetime
 import random
 import re
 import urllib
 
@@ skipping 259 matching lines @@
     self.m.chromium.runhooks(env=env, **kwargs)
 
   def peek_gn(self):
     """Runs gn and compares flags with gyp (fyi only)."""
     # TODO(machenbach): Whitelist all builders eventually.
     if 'linux' not in self.m.properties['buildername'].lower():
       return
     gyp_build_dir = self.m.chromium.c.build_dir.join(
         self.m.chromium.c.build_config_fs)
     with self.m.tempfile.temp_dir('v8_gn') as gn_build_dir:
-      self.m.chromium.run_gn(
-          use_goma=True, build_dir=gn_build_dir, ok_ret='any')
+      step_result = self.m.python(
+          name='patch mb config (fyi)',
+          script=self.resource('patch_mb_config.py'),
+          args=[
+            self.m.path['checkout'].join('infra', 'mb', 'mb_config.pyl'),
+            self.m.raw_io.output(),
+          ],
+          step_test_data=lambda: self.m.raw_io.test_api.output('[mb config]'),
+          ok_ret='any',
+      )
+      use_goma = (self.m.chromium.c.compile_py.compiler and
+                  'goma' in self.m.chromium.c.compile_py.compiler)
+      self.m.chromium.run_mb(
+          self.m.properties['mastername'],
+          self.m.properties['buildername'],
+          name='generate_build_files with gn (fyi)',
+          use_goma=use_goma,
+          mb_config_path=self.m.raw_io.input(step_result.raw_io.output),
+          build_dir=gn_build_dir,
+          ok_ret='any',
+      )
       self.m.python(
           'compare build flags (fyi)',
           self.m.path['checkout'].join('tools', 'gyp_flag_compare.py'),
           [gn_build_dir, gyp_build_dir, 'all', 'all'],
           ok_ret='any',
       )
 
   @property
   def build_environment(self):
     if self.m.properties.get('parent_build_environment'):
@@ skipping 869 matching lines @@
   def report_culprits(self, culprit_range):
     assert culprit_range
     if len(culprit_range) > 1:
       text = 'Suspecting multiple commits'
     else:
       text = 'Suspecting %s' % culprit_range[0][:8]
 
     step_result = self.m.step(text, cmd=None)
     for culprit in culprit_range:
       step_result.presentation.links[culprit[:8]] = COMMIT_TEMPLATE % culprit